Lubricating oil compositions containing sulfonates



United States Patent Ofiice 3 ,121,687 Patented Feb. 18, 1964 3,121,687 LUBRICATING GIL CUMPOSETIUNS CONTAINING SULFGNATES Guy M. Verley, Harvey, 1111., assiguor, by memo assignments, to Sinclair Research, Inc, New York, N.Y., a corporation of Delaware No Drawing. Filed lune 30, 1958, Ser. No. 745,331 7 Claims. (Cl. 25233) My invention relates to lubricating oil compositions of particular value as diesel engine crankcase oils.

Lubricating oils commonly include detergents which enhance the performance of such oils by reducing sludge deposit on engine parts. Basic barium mahogany sulrfonates or basic calcium mahogany sulfonates, for example, are highly effective as such detergents, but increased oil oxidation rates are incidental to their use.

It has been proposed to reduce the basicity of basic barium or calcium mahogany sulfonates with a weak acid in order to decrease their propensity to raise the oxidation rates of the oils in which they are employed as detergents. Thus at least partial neutralization of these basic alkaline earth metal mahogany sulfonates has had the desired effect and has not significantly diminished the detergent or corrosion characteristics of the oils containing them. However, I have observed that the viscosity rise of oils containing these at least partially neutralized basic alkaline earth metal mahogany sulfonates in service is usually high. Thus, for example, reducing the basicity of basic barium mahogany sulfonates to zero base number (a term defined in ASTM D974) at a pH of 8 (measured in accordance with ASTM D- 664) by carbonic acid neutralization results in lubricants displaying an abnormal increase of viscosity. Such an increase is, of course, undesirable.

I have now found that the viscosity rise in service of mineral oils containing a minor proportion of at least partially neutralized basic alkaline earth metal mahogany sulfonates can be eifectively reduced by incorporating a minor proportion of a zinc mahogany sulfonate, particularly' one having a high metal equivalents content, therein. Such a zinc mahogany sulfonate is present in the lubricat ing oil compositions of my invention in an amount of from about 0.1 to 1.0 mole, and preferably from about 0.15 to 0.3 mole, of zinc per mole of the alkaline earth metal, e.g., calcium, barium or mixtures thereof, present in the form of at least partially neutralized basic mahogany sulfonates. Further, while the zinc can be present in the form of a mahogany sulfonate having a metal content as low as 0.5 to 1.0 equivalents of the acid number (a term defined in ASTM D-974) of its parent mahogany sulfonic acid in order to obtain a significant reduction of the viscosity rise, greater reduction is realized when the metal content is in the range of from about 1.0 to 3.0 equivalents. The preferred metal content is about 2.0 equivalents.

I have also found a method of producing new and useful concentrates of mahogany sulfonates of metals of group II of the periodic system having atomic numbers in the range of 19 to 57 inclusive (calcium, zinc, strontium, cadmium and barium) which have high metal equivalents contents. Such a concentrate of zinc mahogany sulfonates is particularly useful in the lubricating oil compositions of my invention for the purpose of reducing the viscosity rise in serivce that the at least partially neutralized basic alkaline earth metal mahogany sulfonates contained therein would otherwise produce.

The base oil in the lubricating oil compositions of my invention can be any petroleum oil suitable for service as an engine lubricant. It can be, for example, a solventt-reated Mid-Continent neutral, a blend of solvent-refined Mid-Continent neutral with bright stock, a solvent-refined lubricating oil fraction from a Pennsylvania crude or an acid-treated Coastal oil. In addition, it can contain additives such as anti-oxidants, pour depressors, viscosity index improvers, anti-form agents and anti-wear compounds. For example, it can contain a minor proportion i.e., 0.1 to 3 par-ts of anti-oxidant concentrate per parts of lubricating oil, of an anti-oxidant of the class consisting of reaction products of terpenes and phosphorus trisulfide or pentasulfide and their derivatives such as are described in US. Pat. No. 2,486,188, issued October 25, 1949, to May. Another suit-able anti-oxidant is disclosed in US. Pat. No. 2,621,172, issued December 9, 1952, to Teter.

The at least partially neutralized basic alkaline earth metal mahogany sulfonates in the lubricating oil compositions of my invention are defined as those having an alkaline earth metal content greater than the alkaline earth metal equivalent of the acid number of the parent mahogany sulfonic acid and having a basicity less than that which would result from producing the alkaline earth metal mahogany sulfonate merely by reacting an alkaline earth metal hydroxide 'with a mahogany sulfonic acid. These at least partially neutralized basic alkaline earth metal mahogany sulfonates can be obtained by a carbonation procedure such as is described in the Kleinholz application Serial No. 324,597, filed December 6, 1952, and now abandoned. Thus, for example, a basic barium mahogany sulfonate concentrate can be contacted with carbon dioxide at atmospheric or slightly higher pressure until its strong basicity to phenolphthalein is destroyed and a final pH of 7.5 measured in accord ance with ASTM D664 is obtained. Such a neutralization can also be effected by treating the basic alkaline earth metal mahogany sulfonates with any weak acid. An inorganic acid having a neutralization constant of from 10- to 10- is preferred and carbon disulfide, carbon dioxide and phenols are suitable. However, for the lubricating oil compositions of my invention, partial neutralization of the basic alkaline earth metal mahogany sulfonates to a pH of from about 8 to 10, rather than complete neutralization to a pH of from about 6.5 to 7.5, is preferred and neutralization to a pH of from 9.5 to 10 is particularly advantageous, since the neutralizing power of the resulting mahogany sulf'onates towards acids present in the oil compositions is excellent and since the initial strength of these sulfonates is not yet sufficiently great enough.

The basic alkaline earth met-a1 mahogany sulfonates which are at least partially neutralized in the lubricating oil compositions of my invention can have an alkaline earth metal equivalents content of tfI'OHl 1.25 to 2 equivalents of the acid number of the parent mahogany sulfonic acids, as is the case in presently known lubricating oils, or they can have substantially higher metal equivalents contents, such as from about 2.5 to 6.0 equivalents of the acid number of the parent mahogany acids, so

long as they 'alford these compositions amounts of the alkaline earth metals, e.g., calcium, barium or mixtures thereof, in the range of from about 0.1 to 2.0, preferably 0.6 to 1.2, percent by weight. The use of the Zinc mahogany sulfonate in accordance with my invention not only comprehends such high alkaline earth metal equivalents contents, but has been found to be particularly advantageous when my lubricating oil compositions contain calcium mahogany sulfonates having a calcium content of from about 4 to 6 equivalents or barium mahogany sulfonates having a barium content of from about 3 to 4 equivalents.

The basic alkaline earth metal mahogany sulfonates V which are at least partially neutralized in the lubricating oil compositions of my invention can be obtained by the procedure set forth in US. Pat. No. 2,711,396, issued June 21, 1955, to Dorinson. Similarly, a concentrate of zinc mahogany sulfonates in a petroleum solvent and containing less than about 1 equivalent of Zinc can be produced by an adaptation of this process. But this procedure, which involves sulfonating a petroleum oil to form mahogany sulfonic acids and treating such acids with a metal hydroxide or oxide and water, is not satisfactory for the production of zinc mahogany sulfonates such as are preferably contained in the lubricating oils of my invention, i.e., those having from about 1.0 to 3.0 equivalents, and another process has had to be found.

According to the process of my invention, basic mahogany sulfonates of metals of group H of the periodic system having atomic numbers in the range from 19 to 57 inclusive (calcium, zinc, strontium, cadmium and barium) the metal equivalents contents of which are greater than the metal equivalent of the acid number of the parent mahogany sulfonic acids can be conveniently prepared by forming a mixture of a petroleum solvent, e. g., kerosene or mineral oil, a mahogany sulfonic acid, and at least one glycol ether and adding to this mixture an oxide or hydroxide of one of such group II metals. The amount of petroleum solvent employed in the process of my invention is not critical. Usually, however, it will be about 1 to 5 times the weight of the mahogany sulfonic acid. It is, on the other hand, advantageous to include a minor proportion, i.e., from about 1 to 2 weight percent based on the solvent and the mahogany sulfonic acid, of tertiary octylphenol sulfide in the solvent-acid-mixture to enhance the promoting action of the glycol ether in the formation of mahogany sulfonates of high metal equivalency. Further, this formation is effected by heating the mixture to from about 65 C. to 260 C., preferably from 200 C. to 240 C.

Suitable glycol ethers for use in the process of my invention include those of the formulae:

wherein x and z are integers in the range of to 6 inclusive and y is an integer in the range of 1 to 100 inelusive. Included in such classes of ethers is, for example, diethyl Carbitol (diethyl ether of diethyleneglycol). The amount of the glycol ether used in about 1 to 20 percent by weight based on the combined weight of the petroleum solvent and the mahogany sulfonic acid. percent by weight of the glycol ether is the preferred amount.

The amount of the group II metal used in the process of my invention depends on the mahogany sulfonate to be made and the desired metal content in such sulfonate. Generally, the desired metal content will be in the range from about 1 to 6 equivalents and the amount of metal employed to achieve it will exceed the amount necessary to react the mahogany sulfonic acid. Thus, to obtain a zinc mahogany sulfonate having a metal equivalents content of from about 1 to 3 equivalents, about 2 to 10 equivalents are reacted with the mahogany sulfonic acid.

This amount of metal is, of course, supplied as zinc oxide or zinc hydroxide. if the oxide of the metal is used in the process of my invention, Water is added to the petroleum solvent-mahogany sulfonic acid-glycol ether mixture in an amount of up to 3 weight percent based on the combined weight of the solvent and acid. 1 percent by weight of water is preferred. The water is not, however, required when the hydroxide of the group II metal is used.

The lubricating oil compositions of my invention are made by blending together with the base oils a concentrate of the at least partially neutralized basic alkaline earth metal mahogany sulfonates, a concentrate of the zinc mahogany sulfonates, and, if desired, an anti-oxidant or the like. The process of my invention for making the various mahogany sulfonate concentrates and the process of making the anti-oxidant will be further illustrated by the following examples:

EXAMPLE I Carbonated Barium Mahogany Sulfonate Concentrate of 2 Equivalents Metal Content A mahogany acid was made by sulfonating a sweet West Texas dewaxed gas oil (215 SUS at F.) by three dumps per barrel of oil of 30 lb. of oleum. The acid oil was air blown and sludge was removed. The air blown, sludge free, acid oil was then added rapidly with vigorous stirring to a slurry of 3 equivalents of barium oxide in 5 times its weight of water. The mix was dehydrated by heating to 300 F. and was then filtered; This yielded a barium mahogany sulfonate concentrate containing 3.66% by weight barium (by sulfate ash determination) and having a base number of 12 at pH 8 as determined by ASTM D -974 and ASTM D-664. The barium content of the barium mahogany sulfonate was 2 equivalents of the acid number of the parent mahogany sulfonic acid. Thus, in other words, 2 of the 3 equivalents of barium admixed with the acid oil combined with the acid oil. This barium mahogany sulfonate was neutralized to zero base number at pH 8 by bubbling moist carbonic acid through it.

EXAMPLE II Carbonated Calcium Mahogany Sulfonate Concentrate of 5 Equivalents Metal Content One part by weight of sweet West Texas dewaxed gas oil (215 SUS at 100 F.) was diluted with three parts by Weight of acid treated kerosene and the mixture sulfonated by sulfuric anhydride in a continuous system to give a kerosene solution of mahogany acids of 6.3 acid number at pH 8. 100 parts by weight of this kerosene solution was blended with Water (1.5 parts by weight), diethyl Carbitol (4 parts by weight) and tertiary octylphenol sulfide containing 6.3 Weight percent sulfur (1.25 parts by weight). Calcium oxide (1.9 parts by Weight, i.e., 6 equivalents) was added with good stirring at room temperature. The mixture was heated to 88 C. and blown with carbon dioxide for 6 hours. The temperature of the mixture increased to 240 C. in the first two hours. 90 percent of the kerosene solvent distilled at atmospheric pressure in the 6 hours. The unreacted solids were filtered at C. and the solution was topped of the remaining kerosene by heating to 180 C. pot temperature at 0.2 mm. Hg absolute pressure. Clear calcium mahogany sulfonate concentrate (26 parts by Weight) containing 4.56 weight percent calcium (by sulfate ash determination) and having a base number of 44 at pH 4 as determined by ASTM D-974 and ASTM D-664 was obtained. The calcium content of the calcium mahogany sulfonate was 5.1 equivalents of the acid number of the parent mahogany sulfonic acid. The tertiary octylphenol sulfide enhances the promoting action of the glycol ether towards obtaining high metal equivalents content.

EXAMPLE III Carbonated Barium Mahogany Sulfonate Concentrate of 4 Equivalents Metal Content 100 parts by weight of the kerosene solution of Example II was blended with water (1.5 parts by weight), diethyl Carbitol (4 parts by weight), and tertiary octylphenol sulfide containing 6.3 weight percent sulfur (1.25 parts by weight). Barium oxide (6 parts by weight, i.e., 6 equivalents) was added and the neutralization was effected by the procedure described in Example II. Clear viscous barium mahogany sulfonate concentrate (27 parts by weight) containing 12.6 weight percent barium (by sulfate ash determination) and having a base number of 68 at pH as determined by ASTM D-974 and ASTM D664 was obtained. The barium content of the barium mahogany sulfonate was 4 equivalents of the acid number of the parent mahogany sulfonic acid.

EXAMPLE IV Zinc Mahogany Sulfonate Concentrate of 2 Equivalents Metal Content To 100 parts by weight of the kerosene solution of Example II was added 1 part by weight of water, parts by weight of diethyl Carbitol and 1.7 parts by weight of zinc oxide, i.e., 3 equivalents. The mixture was heated with stirring at atmospheric pressure to 230 C. in 4 hours. 80 weight percent of the kerosene distilled during this heating. The residue was cooled to 120 C. and then topped at 0.2 mm. Hg absolute pressure until a port temperature of 180 C. was reached. The mixture was then filtered and a concentrate of zinc mahogany sulfonate (24.8 parts by weight) containing 2.78 weight percent of zinc (by sulfate ash determination and having an acid number of 23.2 at pH 8 and a base number of 9.39 at pH 4 as determined by ASTM D-974 and ASTM D-664 was obtained. The zinc content of the zinc mahogany sulfonate was 2 equivalents of the acid number of the parent mahogany sulfonic acid.

EXAMPLE V A nti-Oxidant To 502 gallons of pinene contained in a jacketed kettle at 132 C., there is added 1350 pounds of phosphorus pentasulfide in 75 pound batches over a period of 60 to 90 minutes. During this period, the kettle contents are stirred and the temperature is maintained at 132 C. to 143 C. by circulating cooling water through the jacket. Following the addition of phosphorus pentasulfide, the resulting mixture is stirred for 6 hours while the temperature is maintained at 132 C. to 138 C. Then, there is added 350 pounds of a mixture of high boiling aliphatic phenols in which the alkyl groups have about 4 carbon atoms and which is sold under the trademark of C.C.C. After this addition, the mixture is digested at 135 C. for 4 hours, 65 pounds of 2-ethylbutanol is added, and the digestion is continued for another 4 hours. 892 gallons of Mid-Continent oil (80 viscosity index, 200 SUS at 100 F.) is added to the kettle. The mixture is then cooled to 38 C. and 78 pounds of sulfur dichloride is carefully added. Following this addition, the temperature is raised to about 93 C. and the mixture is digested for about 4 hours. pounds of lime and from 50 to 100 pounds of Hyflo Super-Cel, a proprietary diatomaceous silica, are then added and the mixture is digested for 3 hours at 90 C. The lime is used as a neutralizing agent and the diatomaceous silica as an aid to filtration. At the end of the 3 hour period, the mixture is filtered and an anti-oxidant con centrate of the following properties is obtained:

Gravity, API 13.6 Flash, "F 210 Fire, 'F 410 Viscosity at F 1018 Acid No 0.90 Phosphorus, wt. percent 3.30 Sulfur, wt. percent 8.73

The following tables illustrate the compositions of my invention and their characteristics. Table I sets forth blends of a base oil and the concentrates of Examples I to V to form suh compositions. These blends are highly suitable diesel engine crankcase lubricating oils and were made by admixing the base oil, a Coastal oil of about 1000 to 1100 SUS at 100 F., with the concentrates at F. to F. The term parts used in Table I means parts by weight.

TABLE I Blend LA: Parts Barium mahogany sulfonate concentrate of Example I 22 Anti-oxidant concentrate of Example VI 2.75 Base oil to 100 Blend I-B:

Barium mahogany sulfonate concentrate of Example I 22 Anti-oxidant concentrate of Example VI 2.75 Zinc mahogany sulfonate concentrate of Example IV 4 Base oil to 100 Blend II-A:

Calcium mahogany sulfonate concentrate of Example II 6 Anti-oxidant concentrate of Example VI- 2.25 Base oil to 100 Blend II-B:

Calcium sulfonate concentrate of Example IL- 6 Anti-oxidant concentrate 2.25 Zinc sulfonate concentrate of Example 1V 1.8 Base oil to 100 Blend III-A:

Barium sulfonate concentrate of Example III 7 Anti-oxidant concentrate 2.75 Base oil to 100 Blend lIL-B:

Barium sulfonate concentrate of Example III 7 Anti-oxidant concentrate 2.75 Zinc sulfonate concentrate of Example IV 1.8 Base oil to 100 Blend I-C:

Barium sulfonate concentrate of Example I 22 Anti-oxidant concentrate 2.75 Base oil to 100 Blend I-D:

Barium sulfonate concentrate of Example I 22 Anti-oxidant concentrate 2.75 Zinc sulfonate concentrate of Example IV 8 Base oil to 100 Blend I-E:

Barium sulfonate concentrate of Example I 22 Anti-oxidant concentrate 2.75 Zinc sulfonate concentrate of Example IV 4 Base oil to 100 Blend IF Barium sulfonate concentrate of Example I--- 18 Anti-oxidant concentrate 2.75 Zinc sulfonate concentrate of Example IV 4 Base oil to s 100 The viscosity rises, acid numbers, and insoluble formations shown in Table II of the blends of Table I were determined by a method which gives results paralleling the viscosity rise, acid number, and formation of insolubles determined by engine tests. The method comprises bubarees? bling liters of oxygen/hr. through 300 grams of the blend maintained at 285 F., and, at 48 hour intervals, taking 60 gram samples and adding 60 grams of fresh blend to make up for the sample withdrawn. Withdrawal of samples and replacement in this manner allows tests were carried out under the following conditions: each run 300 hours without oil change, at 1200 r.p.m., 3O B.H.P., 220 F. to 225 F. oil sump temperature, 225 F. :5 F. oil gallery temperature, 175 F. water temperature at the outlet. The test results are set forth in for the average makeup of oil in diesel engines. Table V.

TABLE II Pcntane Molar Maximum Acid No. Insolublcs, Ratio, Vis. Rise, at 240 Hrs., Wt. Per- Ratio of Blend Metals, Percent Zn/Ba SUS/lOO AS'IM cent 0, 240 Viscosity 0r Ca F. D-974 Hrs, Rise 1 ASTM D-893 At 144 Hrs. At 144 Hrs.

Ba .81% 024 7. 36 4. 883 Ba .26 438 7. 06 4. 837 1. 9 Ba .8l%, Z l3 1, 165 9. l4 6. 959 0.8 Be 156%, 16 604 7.00 4. 994 l. 5

1 Ratio of viscosity rise of the blend without zinc sulionate to viscosity rise of the blend with zinc sulionate.

The data of Table II indicate that the viscosity of all blends containing carbonated basic barium or calcium mahogany sulfonates rises substantially during use, that the viscosity rise is greater for blends of higher metal equivalent (Blend I'IIA), and that viscosity rise is reduced to normal levels by incorporation in the lubricating oil of Zinc mahogany sulfonate. Further, the data indicate that zinc mahogany sulfonate of metal equivalent greater than 1 (Blends I-B, IIB and I I-B) is more effective in reducing viscosity rise than is zinc mahogany sulfonate of metal equivalent less than 1 (Blends I-D, I-E and PF). The data also indicate that the zinc mahogany sulfonate does not have an appreciable effect on the acid number or the insolubles of the lubricating oil after oxidation.

The blends set forth in Table III below, were formulated and subjected to engine testing. The term parts as used in this table means parts by Weight.

A partial analysis of the blends of Table III is set forth in Table IV.

TABLE IV Percent Percent Percent Molar P Ba Zn Ratio, Zn/Ba Blend I-G 0.085 Blend I-H 0.078 0. 78 0.101 0.27

Blends LG and IH were tested under conditions which give comparable results in a GM 2-71 diesel engine. The

TABLE V Blend- I-G I-H Deinerits'.

Ring Sticking 0.5 0. l Skirt Lacquer" 0.3 0. 6 Liner Lacquer 0.0 0.0 Ring Groove Deposits. 2. 7 1. 6 Area Above Top Ring 2. 6 5. 5 Ring Land Deposits... 11 0. 0 Port Restriction 1. 2 0.5 Wear:

Average Gap Increase Ring No. 1.- inches 0. 006 0. 003 Average Gap Increase Ring No. 2.. do 0. 0045 0.003 Average Gap Increase Ring No. 3.. 1o 0. 004 0.0025 Average Gap Increase Ring N0. 4 d0 0.0035 0.002 Liner Wear, Transverse do 0. 0016 0. 0009 Liner Wear, Longitudinal d0 0.0008 0.0002 Oil-Pb Bearing Weight Loss Rods". grams" 0.005 0.010 Cu-Pb Bearing Weight Loss Mains do. 0. 009 0.026 Oil Consumption, Lbs/Hour 0. 085 0.070 Used Oil Analysis:

Vis. Increase at SUS 577 270 Percent Vis. Increase at 100 F 56 27.4 Vis. Increase at 210 F. SUS... 30. G 11.7 Percent Vis. Increase at 210 F 52 15. 2 Acid Ne. Increase (ASTM 2.14 1.06 Pentane Insolubles, Wt. Percent (ASTM D893) 3. 499 3. 921 Benzene Insolubles, Wt. Percent (ASTM D-893) 3. 425 3. 377 Insoluble Resins, Wt. Percent (ASTM D893) 0. 074 0. 544

The data set forth in Table V confirm the data of the oxidation tests set forth in Table II. The data of Table V also indicate that liner and ring wear are approximately halved by the addition of the zinc mahogany sulfonate.

I claim:

1. A lubricating oil composition comprising a major proportion of a mineral base oil; about 0.1 to 2.0 percent by weight of an alkaline earth metal selected from the group consisting of calcium, barium and mixtures thereof, the alkaline earth metal being present in the mineral base oil as a basic alkaline earth metal mahogany sulronate neutralized to a pH of about 6.5 to 10 and having an alkaline earth metal content about 1.25 to 6.0 times greater than the'alkaline earth metal equivalent of the acid number, as determined by ASTM procedure D-974, of the parent mahogany sulfonic acid and having a basicity less than that which would result from producing the alkaline earth metal mahogany sulfonate merely by reacting the hydroxide of the alkaline earth metal with the parent sulfonic acid; and, a minor proportion of a zinc mahogany sulfonate, the zinc mahogany sulfonate being present in the mineral base oil in an amount suflicient to aiford the composition a ratio of 0.1 to 1.0 mole of zinc per mole of the alkaline earth metal.

2. The lubricating oil composition of claim 1 in which the metal content of the Zinc mahogany sulfonate is from about 0.5 to 3.0 times the metal equivalent of the acid number, as determined by ASTM procedure D-974, of the parent sulfonic acid of the zinc mahogany sulfonate.

3. The lubricating oil composition of claim 1 in which the metal content of the zinc mahogany sulfonate is about 2 times the metal equivalent of the acid number, as determined by ASTM procedure D-974, of the parent sulfonic acid of the zinc mahogany sulfonate.

4. The lubricating oil composition of claim 1 in which the metal content of the zinc mahogany sulfonate is from about 1.0 to 3.0 times the metal equivalent of the acid number, as determined by ASTM procedure D-974, or the parent sulfonic acid of the zinc mahogany sulfonate.

5. The composition of claim 1 in which the basic sulfonate has been partially neutralized by carbonation to a pH of about 8 to 10.

6. The composition of claim in which the alkaline earth metal is calcium present in an amount of about 0.6 to 1.2 percent, the calcium content of the calcium sulfonate is about 3 to 4 equivalents, the pH is 9.5 to 10, the molar ratio of Zinc to calcium is about 0.15 to 0.3 and about 2 equiva- References Cited in the file of this patent UNITED STATES PATENTS 2,491,649 Duncan et al Dec. 20, 1949 2,535,101 Sproule et a1 Dec. 26, 1950 2,616,911 Assetf et al Nov. 4, 1952 2,616,924 Asseff et a1 Nov. 4, 1952 2,821,548 Verley Jan, 28, 1958 2,837,549 Reeves et al June 3, 1958 2,842,578 Pikl July 8, 1958 2,850,455 Kern et al Sept. 2, 1958 2,856,361 Schlect Oct. 14, 1958 2,916,451 Faust Dec. 8, 1959 FOREIGN PATENTS 553,234 Great Britain May 13, 1943 788,408 Great Britain Jan. 2, 1958 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 121,68; February 18, 1964 Guy M. Verley It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line for "equivalents" read equivalent column 2 line 1 for ""serivce" read service line 1 12, for "anti-form" read antiefoam column 3, line 62, for "in" read is column 5, line 37, for "port" read pot column 6, lines 24, 29 and 36, for "Example VI each occurrence, read Example V column 7, line 41, for "and II-B" read and III-B line 54, for "Example VI" read Example V line 60, for "Example V" read Example IV column 9, line- 26, for 3 to 4" read 4 to 6 -Q Signed and sealed this 20th day of April 1965. (SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attcsting Ufficer Commissioner of Patents 

1. A LUBRICATING OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF A MINERAL BASE OIL; ABOUT 0.1 TO 2.0 PERCENT BY WEIGHT OF AN ALKALINE EARTH METAL SELECTED FROM THE GROUP CONSISTING OF CALACIUM, BARIUM AND MMIXTURES THEREOF, THE ALKALINE EARTH METAL BEING PRESENT IN THE MINERAL BASE OIL AS A BASIC ALKALINE EARTH METAL MAHOGANY SULFONATE NEUTRALIZED TO A PH OF ABOUT 6.5 TO 10 AND HAVING AN ALKALINE EARTH METAL CONTENT FROM 1.25 TO 6.0 TIMES GREATER THAN THE ALKALINE EARTH METAL EQUIVALENT OF THE ACID NUMBER, AS DETERMINED BY ASTM PROCEDURE D-974, OF THE PARENT MAHOGANY SULFONATE ACID AND HAVING A BASICITY LESS THAN THAT WHICH WOULD RESULT FROM PRODUCIUNG THE ALKALINE EARTH METAL MAHOGANY SULFONATE MERELY BY REACTING THE HYDROXIDE OF THE ALKALINE EARTH METAL WITH THE PARENT SULFONIC ACID; AND, A MINOR PROPORTION OF A ZINC MAHOGANAY SULFONATE, THE ZINC MAHOGANY SULFONATE BEING PRESENT IN THE MINERAL BASE OIL IN AN AMOUNT SUFFICIENTE TO AFFORD THE COMPOSITION A RATIO OF 0.1 TO 1.0 MOLE OF ZINC PER MOLE OF THE ALKALINE EARTH METAL. 